A thin copper wire of length $l$ increase in length by 1%, when heated from 0$℃$ to 100$℃$. If a thin copper plate of area $2l imes l$ is heated from 0$℃$ to 100$℃$, the percentage increase in its area would be

Question

A thin copper wire of length $l$ increase in length by 1%, when heated from 0$℃$ to 100$℃$. If a thin copper plate of area $2l 	imes l$ is heated from 0$℃$ to 100$℃$, the percentage increase in its area would be

Dr. Abubacker · Accepted Answer

(d) $l = l_{0}\left( 1 + \frac{1}{100} ight)$
$	herefore\ 2l^{2} = 2l_{0}^{2}\left( 1 + \frac{1}{100} ight)^{2}$
Or $2l^{2} - 2l_{0}^{2} = 2l_{0}^{2} 	imes \frac{2}{100}$
Or $\mathrm{\Delta}S = S\  	imes \frac{2}{100}\ \ or\ \frac{\mathrm{\Delta}S}{S} = \frac{2}{100} = 2\%$

Q. A thin copper wire of length $l$ increase in length by 1%, when heated from 0$℃$ to 100$℃$. If a thin copper plate of area $2l \times l$ is heated from 0$℃$ to 100$℃$, the percentage increase in its area would be

Explanation

Reviewed by Dr. Abubacker

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